El Thursday 12 June 2008 08:12:08 praveen dandin escribió:
> 1) Above description says that the CANCEL request (if no branch parameter
> is present) is matched to a transaction (say INVITE txn) if top Via header
> field match that of the request. Does this mean branch parameter in both
> the requests are not matched (as the description is for requests without
> branch param)??
AFAIK when comparing a header with parameters ("branch") and a header with no
parameters they don't match.
> 2) Is it valid to match a CANCEL request without branch parameter to an
> INVITE request with branch parameter when rest of the above headers
> (RFC3261 section 17.2.3 description) are identical??
CANCEL is sent hop by hop and each SIP node (UAC and intermediate proxies)
will create the transaction (if stateful) for the INVITE when forwarding it.
So, if a UAC generates a INVITE RFC3261 compliant (with "branch" param) there
is no reason at all to generate a CANCEL without it.
And if a proxy creates a user transaction to forward an INVITE and
includes "branch" in the Via added, and later receives a CANCEL upstream it
must generate a CANCEL so it must create another user transaction. Why in
this case wouldn't it add the "branch" param?
--
Iñaki Baz Castillo
[EMAIL PROTECTED]
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
